Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for transmitting an indication in a wireless communication system.
Related Art
Universal mobile telecommunications system (UMTS) is a 3rd generation (3G) asynchronous mobile communication system operating in wideband code division multiple access (WCDMA) based on European systems, global system for mobile communications (GSM) and general packet radio services (GPRS). A long-term evolution (LTE) of UMTS is under discussion by the 3rd generation partnership project (3GPP) that standardized UMTS.
The 3GPP LTE provides a multimedia broadcast/multicast service (MBMS). The MBMS is a service which simultaneously transmits data packets to multiple users. If a specific level of users exists in the same cell, the respective users can be allowed to share necessary resources so that the plurality of users can receive the same multimedia data, thereby increasing resource efficiency. In addition, a multimedia service can be used with a low cost from the perspective of users.
In an area, a specific base station (BS) may use multiple frequencies at the same time. For using radio resources efficiently, the network may provide the MBMS on only one frequency among the multiple frequencies, and may provide dedicated bearers to each user equipment (UE) on all multiple frequencies. In this case, if the UE, which receives a service using the dedicated bearer in a frequency not providing the MBMS, wants to receive the MBMS, the UE may have to be handed over to a frequency providing the MBMS.
For this, a network control option may be adopted as a basic architecture for handling the MBMS. The network may be informed about UE's interest in the MBMS by the UE, and then the network tries to ensure that the UE is able to receive the MBMS. That is, if the UE would like to receive the MBMS, the UE transmits an MBMS interest indication to the BS. The MBMS interest indication provides MBMS interest information at the level of a frequency rather than of an individual service, and indicates UE's interest in MBMS frequency reception. Upon receiving the MBMS interest indication from the UE, the BS acknowledges that the UE wants to receive the MBMS, and makes the UE move to a frequency providing the MBMS. The MBMS interest indication may indicate that the UE wants to receive the MBMS. The MBMS interest indication may include information on the frequency which provides the MBMS that the UE wants to receive. The UE may obtain the information on the frequency providing the MBMS that the UE wants to receive, by receiving a system information block (SIB)-15 from a serving cell. The UE may transmit the MBMS interest indication whenever the UE's interest changes.
The UE may transmit MBMS interest indications many times. Excessive transmissions of MBMS interest indications will cause the network to be overloaded.
Accordingly, a method for restricting transmission of MBMS interest indications may be required.